Tre e C a re A d v i s o r N ew s l e t t e r http:// www.mntca.org
Dave Hanson and Gary Johnson, Managing Editors
Inside This Issue:
Volume 11 Number 3
I hate to say it, but summer is fading fast!
Who’s Confused? By Dave Hanson
1 Has anyone noticed an elm tree flagging this year? City foresters and crews all
Quick Hits / Volunteer Opps By Gail Soens
2
over the state are busy trying to stay ahead of Dutch Elm Disease. It is proving to be a banner year with most cities doubling or tripling the numbers of removals over recent years. This issue contains a couple of articles from urban forestry students and I think
Had to be There! By Cliff Johnson
you’ll enjoy them. The first is a second look at ginkgo while the other discusses the
Putting Down Roots: By Cliff Johnson
3 value of yard (landscape) trees.
Giving The Ginkgo… By Eric Mader
5
Yard Tree Worth Money? By Brady Boyce
8
Feast or Famine? By Dave Hanson
10
Frog and Toad - Habitats 11 By Linda Guertler Contacts Intro to Asclepias spp.
Linda Guertler returns - one of the spring arrivals to the TCA program with an introduction to frog and toad… She reminds us that it is not all about trees. Related to Linda’s habitat article, see page 24 for a look at some of our native milkweeds (Asclepias spp.) And remember - we’re still in a low risk period of the Oak Wilt Season… Dutch elm disease season... Fireblight is out there… Don’t worry, there will be time to prune later!
Who’s Confused?
24
There are several representatives of conifers gracing the State of Minnesota. Minnesota is blessed with northern white cedar along its northern shorelines and east-
Eastern Hemlock Photo: Dave Hanson
ern red cedar existing on dry, rocky bluffs and in dry prairies. Bog or black spruce shares the swamps with tamarack while skunk or white spruce works out life in the forest. White pine, red (Norway) pine and jack pine intermingle over vast stretches of Northern Minnesota drawing vacationers as they drew the early loggers and settlers. For the lucky adventurer there may also be an encounter out there with eastern hemlock.
With all of this variety, Minnesotans should develop the skill to differentiate the families and should be able to answer – “What is a fir?” or
Continued on page 21
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Quick Hits The Tree Care Advisors of Dakota County have a marvelous opportunity, which we would like to share with Tree Care Advisors from other Counties. There is a wooded area in UMore Park which is home to the Master Gardener Research, Outreach and Education site located off of 160th Street just south of Rosemount. This area was planted as part of a forestry project back in the 40's and 50's. We would like to build an interpretive trail through this area. The focus of the trail will be multi-faceted: tree id; disease and insect issues; tree spacing and other cultural conditions; invasive species and soils. We have Pat Weicherding, Dave Hanson and Carl Vogt advising the project; with Mel Bauman as the Interpretive Trail Artist. The trail is in the initial phases of development. Once we finish a tree inventory and a rudimentary plan, we would like to invite Tree Care Advisors to come spend a day or more with us clearing buckthorn, pruning, marking trees, spreading mulch etc. This area will be a self-learning trail for any visitors to the park. However, there is also a classroom adjacent to the woods that can be used to teach Tree Care Classes. The woods is a hands on, "all senses" experience and the classroom can utilize all the current technology for teaching. Watch for further updates on the web site/newsletter! Any questions? Contact Gail Soens TCA Dakota County (Check the TCA directory…)
Soil that moves? You needed to have been there… By Cliff Johnson Some of the strangest things happen in the garden. I had an astilbe seedling in a 4inch pot that I intended to transplant when it got bigger. The pot was in a tray of young plants that I walked by frequently. During several walk-bys last week, it appeared that the soil in that pot moved as I passed but I didn’t stop to examine the situation more closely. Soil’s inert; it doesn’t move, right? Next trip by, the soil moved again. This is too weird, I thought, as I set down my pails to take a closer look. Sure enough the soil was moving. The reason? A toad had taken up residence in the center of the pot and scrunched down low each time I walked by. The toad had uprooted the astilbe plant to make a comfortable lair in the cool, moist peat. I didn’t get too upset over the loss of the astilbe. I mean, how many gardeners have mastered the art of growing toads in pots?
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Putting Down Roots - A column in the Chaska Herald. Summer garden reward: less labor, more enjoyment By Cliff Johnson Carver/Scott Tree Care Advisor It took until mid June to get my last flower seedlings – started last winter and grown under lights – transplanted into pots and flower boxes. In my garden, completing the transplanting process marks a transition from busy spring planting to more-leisurely summer maintenance. I finished planting just in time, given the population explosion of mosquitoes and gnats of a few weeks ago. Working outdoors just isn’t as enjoyable as it was during our marvelous fair-weather spring. Many of this year’s flowers and vegetables resemble the corn and soybeans in farmers’ fields – desperately in need of sunshine and heat. Tomatoes planted in the middle of May seem to be standing still. Coleus and impatiens planted in window boxes haven’t grown more than a few inches during the past month. Our wet May and early June triggered widespread outbreaks of anthracnose fungus on trees. Oak, maple, elm and ash trees dropped many lower leaves, causing many homeowners to call me in search of a diagnosis of whether their trees were dying. Most callers sounded relieved when I offered my phone diagnosis of “probably anthracnose...not a big deal.” Anthracnose is common during cool, wet springs. Anthracnose puts stress on trees because they have to grow a new set of leaves, but it doesn’t generally kill trees.
Mugo pine and sawfly damage. Note the damage is on year old needles, not the current growth. Photo: Dave Hanson
Local news media have reported extensively on the high number of mature elms in the Twin Cities that are dying this summer from Dutch Elm Disease (DED). The same wet-weather pattern that favors anthracnose also encourages the spread of DED. I’ve noticed many young elm trees in Chaska and surrounding towns that appear to be dying of DED. Most diseased trees are native elms that grew from seed. Elms can still be planted in yards but make sure you plant disease-tolerant cultivars from a reputable retailer, rather than an elm seedling dug out of the wild. Other common tree problems this spring included leafing-out delays in ash, maples and honey locust. Many terminal-leaf buds on ash trees froze in mid-May and trees had to grow a new set of leaves from secondary buds. With minimal soil moisture (at that time), it took ash trees a while to get their act together. Plentiful May and early June rainfall finally gave ash roots what they needed to fill out their summer foliage. This is the first year in 10 that my blue-spruce trees haven’t been attacked by sawfly larvae, the inch-long green worms that devour new-growth spruce needles. Funny how the sawfly population moves around. I haven’t seen any sawfly larvae on local spruce by I’ve gotten calls about the critters so I know they are active elsewhere in the county.
Frost damage on black ash. Photo taken on 5-20-04. Dave Hanson
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Putting Down Roots ... Many honey locust trees are still recovering from the winter of 2002-03. About all that can be done about dieback on honey locus is to cut away dead wood and hope that the live wood that’s left still has the appearance and shape of a tree. The problem with maples is a little more complicated. Sugar maples, unfortunately, are not suited to the environment we typically put them in – the front or backyard lawn, often in compacted clay where they have to compete with turf for moisture. Most maple tree roots extend laterally in the top one foot of soil so turfgrass is competition when soil moisture is in short supply.
Stressed red maple in late July Photo: Dave Hanson
Tree experts often refer to “maple decline” as the cause of maple trees that fail in yards. It’s a catchall term that encompasses planting errors, too-dry roots, insect predation, compacted soil, winter stress and other factors. I suppose I could be criticized for writing only about problems. Instead of dwelling on the negative, I’ll close with some positive observations. It’s been a marvelous spring for many blooming plants: ‘William Baffin’ climbing rose, honeysuckle vine, Korean lilac, ‘Royal Star’ magnolia, redosier, gray and pagoda dogwood, PGM rhododendron, plum, crabapple and apple trees. Hostas have never looked better. Rudbeckia and purple coneflowers are just days away from blooming. Of course, I’ve also succeeded in growing a bumper crop of weeds.
Above: Magnolia stellata flowers in April. Echinacea purpurea, purple coneflower.
Finally, I was lucky enough to have a pair of robins take up residence this spring in a Norway spruce growing a few feet outside my office window. They wasted no time between broods. The same day the first fledglings left the nest, the male and female robins began fortifying the nest with mud and grass and more blue eggs followed in a few days. The male and female took turns delivering cutworms and other food to their hungry youngsters and the second brood was nearly ready to fledge on June 26. It will be interesting to see whether this energetic couple will try for three-peat.
Photo: Dave Hanson
Prunus - “North Star” cherry fruit on July 2nd Photo: Dave Hanson
GIVING THE GINKGO A SECOND LOOK
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New Cultivars Make This Awesome Urban Tree Even Better By Eric Mader “Oh no. Not another stinkgo! Don’t you know those things have terrible smelling berries?” When city foresters plant a ginkgo these days, that is the reaction they often get. Unfortunately many people mistakenly assume that all ginkgoes produce foul smelling fleshy seeds, but in fact only the female trees do. Unscrupulous or inattentive nursery owners occasionally sell female trees, and new research indicates that in rare instances ginkgoes may actually switch gender! Despite the occasionally annoying smell, ginkgo seeds provide food for wildlife, and are prized as a food source in Asia. In addition recent medical research has identified a series of chemicals called ginkgolic acids which may have potential for new cancer treatments. With all of these benefits, the occasional weird smell really is pretty inconsequential.
Above: Fruit of a ginkgo in July. Below: “Biloba” 2 lobed leaf Photos: Dave Hanson
The other objection people often have to the ginkgo is the gangly appearance of young trees. Young ginkgoes do have a spindly appearance, but mature trees normally have a broad vase-shaped form similar to the American elm. While some people would like to see the ginkgo gone, new cultivars are causing other people to give the ginkgo a second look. With striped leaves, and horizontal or unusual growth habits, these are not your typical boulevard ginkgoes. Among the most exciting of these new cultivars are Rainbow, ‘Streamside’ and ‘Variegata,’ three selections with striped or variegated foliage. Both Rainbow and Streamside are striped with yellow bands, while Variegata is a true green and white variegated variety. Some people have reported problems with individual branches on Variegata reverting back to all green leaves so regular monitoring and occasional pruning is required with this variety. Ginkgo biloba ‘Variegata’
Additional foliage variations are available with ‘Tubifolia, ‘Laciniata,’ and ‘Saratoga.’
Photo: Cor Kwant
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A SECOND LOOK Tubifolia is the most striking of these cultivars with distinctly tubular leaves, curled to resemble small funnels. Lanciniata features deeply divided leaves with a fringed appearance, and Saratoga produces narrower, more triangular leaves than other cultivars. Other cultivars are variations on the ginkgo’s normal shape and growth habit. ‘Pendula’ is a weeping variety that resembles a willow. ‘Horizontalis’ is a massive spreading tree with extremely long horizontal branches. ‘Fastigia’ and ‘Mayfield’ are both extremely tall, columnar trees that resemble certain conifers in the landscape. Additional cultivars are described in Table 1.
Ginkgo biloba ‘Tubifolia’ Photo: Cor Kwant
The fact that the ginkgo can tolerate poor conditions like soil compaction, high soil pH, heat, drought, salt, and air pollution, makes it the ideal urban tree. Even more impressive, a mature ginkgo can live for thousands of years, and has virtually no insect or disease problems. In municipal settings, city foresters already know the ginkgo is unmatched as a boulevard tree. In the home landscape, creative gardeners will discover the ginkgo is easily trained into a variety of forms, from espaliers and hedges, to climbing shrubs which resemble vines. With all these options, the ginkgo is not simply another urban tree—it is a conversation piece. For More Information Boyd Nursery homepage. 2003. http://www.maleginkgo.com Cochran, K. 1998. Ohio State University Cooperative Extension Service homepage. The Marketing Potential of Ginkgo biloba in the United States. http:// ohioline.osu.edu/sc157/sc157_13.html
Ginkgo biloba ‘Golden globe’ Photo: Cleveland - The Ginkgo Pages Website
Major, R.T. 1967. The Ginkgo, the Most Ancient Living Tree. Science. Vol. 157, No. 3794: 1270-1273. Michigan State University Extension Website. 1999. Ginkgo biloba—The Maidenhair Tree. http://www.msue.msu.edu/imp/modzz/00000667.html Ohio State University Extension website. 2004. Ginkgo biloba. http:// www.hcs.ohio-state.edu/hcs/TMI/Plantlist/gi_iloba.html Photos Credits: Kwant, C. 2000. The Ginkgo Pages Website. http://www.xs4all.nl/ ~kwanten/
A SECOND LOOK Name
Comments
Autumn Gold
Deeper golden-yellow fall color, with
Chase Manhattan
broad pyramidal growth habit at maturity. Compact with tiny dark leaves.
Fairmount
Tall, spindly form.
Fastigia
Extremely tall, narrow.
Globus
Column shaped with very large leaves.
Horizontalis
Spreading, less upright form.
Jade Butterfly
Dense, dark foliage in clumps, shrubby
Lacinata
appearance, semi-dwarf. Fringed and deeply divided leaves.
Lakeview
Compact, broad pyramid shape.
Mayfield
Extremely tall, narrow.
Pendula
Weeping form.
Princeton Sentry
Nearly columnar form, being slightly
Prague
wider at the base. Low, spreading, umbrella-shaped.
Rainbow
Striped yellow/green leaves.
Saratoga
Narrower leaves.
Spring Grove
Very dwarfed, less than 3 meters tall.
Streamside
Yellow and green variegated leaves with
Tremonia
little tendency towards reversion. Extreme columnar form like Lombardi
Tubifolia
poplar. Tubular curled leaves.
Variegata
Variegated leaves.
Witch’s Broom
Irregular, deeply lobed leaves.
Table 1. Common Ginkgo Cultivars.
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Ginkgo biloba ‘Mayfield’ Photo: Cor Kwant
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By Brady Boyce
Figure courtesy of Forestry Suppliers, Inc. Table courtesy of Purdue University. See the end of this article for reference links.
Is the Tree in My Yard Worth Money? A common perception of homeowners is that the trees in their yard, especially certain species, can be cut down and sold for a decent amount of cash. This article will evaluate this notion, and you can determine whether or not that walnut in your front lawn can supplement your retirement. The basic issue we are looking at is money, so we must look at how trees are appraised and evaluated. When making wood products, tree value is based largely on volume. This is determined by the log’s length and diameter (which is measured on the small end and inside the bark). As a general rule, logs less than 8 feet long and 18 inches wide are not highly valued. The following picture and table should give you a rough idea of how much volume your tree contains. Also, lengths and diameters are standardized, so round all measurements down (ex: 15’10” log would be considered only 14’ long). However, your tree is probably standing, but there are ways to estimate the current standing volume. Estimate (or measure if you can) the height of the stem from the ground up to one of the following: the first limb, a curve in the trunk, or at a point where it is roughly 8 inches wide—this is your length. Now, measure (in inches) around the tree at a point roughly 4 ½ feet above the ground. Divide this inch measurement by 3.14 to get the diameter, and use the table above to get a volume estimate. What determines a tree’s value? Apart from volume, there are many factors that impact a given tree’s value as wood, most importantly, what will the tree be used for? Trees are used for a great variety of products (from maple syrup to studs), but yard trees are typically only used for high-end products like veneers (thinly sliced, high-quality wood used to overlay items like doors and cabinets) and specialty goods (furniture, gun stocks, etc.). Furthermore, this also relates to the species of the tree. Species vary in terms of properties, uses, looks, and market demand. For example, a species like oak or cherry is useful for furniture or jewelry boxes, but other trees, like aspen or spruce, are most commonly used for paper or plywood. Other factors impact a tree’s value—and usually in a negative way. Wood buyers are very critical of defects—although many are natural and minimally impact the tree itself, they can significantly reduce the quality, quantity and workability of a given piece of wood. Things such as knots, scars, open seams, cracks, large bends, and even low branches will negatively
Is the Tree in My Yard Worth Money? impact (or perhaps completely nullify) the tree’s value. Furthermore, urban environments expose trees to other value-reducing events. Have you ever accidentally hit a tree with the lawnmower/edge trimmer, or have you perhaps nailed a sign to the tree to advertise a garage sale? If you answered yes, then the tree’s value has just been reduced again. These events tend to either damage the tissue of a tree (which can introduce decay) or actually imbed materials (nails, staples, etc.) into the tree. Log buyers are very cautious about purchasing trees from urban environments specifically because of foreign materials. The equipment for processing these logs usually uses a saw or a knife, and striking a piece of metal can be hazardous. Urban-grown trees have other characteristics as well. They are typically grown in open areas tend to be short and have low branching—resulting in trees that have a minimal useable length. In contrast, trees grown in forest conditions are tall and branch farther from the ground. So, what is my tree worth? After all these considerations, let’s assume that your yard tree still qualifies as desirable—how much money is the wood actually worth? Well, it is tough to say since it is greatly dependent on log quality, species, and market demand. The most high-valued species include: red oak, white oak, cherry, walnut, sugar maple, and others. Prices for these species (with veneer quality) may be around 50 cents per board foot. With a hypothetical 25 inch, 20 foot log tree in your yard, this would perhaps produce $300 in revenue. $300 dollars for a large, near-perfect tree may not seem quite worth it; however, if you have multiple trees or an exceptional tree, see the contacts at the end of the article for more information, because you could make some money. And there’s still another cost to consider: tree removal. Tree removal in an urban environment is not cheap—although tough to determine—can cost hundreds or thousands of dollars. Buildings, utility lines, other trees, and additional factors complicate cutting down trees in an urban environment. Any revenue from selling a tree can be overshadowed by the cost of removing it. Is my yard tree valuable even if it can’t be sold for wood? YES—a tree’s value is not solely determined by the wood. Trees can shade your house, which results in lower summer cooling costs, and they can protect your home from cold winter winds and keep the heating bills down. Furthermore, landscaping, specifically with trees, can increase the property value and resale price of your home by well over 10 percent. So, that walnut is valuable, but the benefits are likely greater if it is left standing. For more information about appraisals/removals: Extension Service Forest Resources Office: (612) 624-3020 DNR Information Center: (651) 296-6157 or (888) MINNDNR Minnesota Society of Arboriculture: http://www.isa-msa.org International Society of Arboriculture: http://www.isa-arbor.com Links: Forestry Suppliers, Inc. http://www.forestry-suppliers.com/t01_pages/ tt_pdf/1211_ScaleStick.pdf Purdue University – Log and Tree Scaling Techniques http://www.agcom.purdue.edu/agcom/Pubs/ FNR/FNR-191.pdf
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One thing to keep in mind: Typically, trees in your lawn or other “high maintenance” portions of your property will be valued differently than trees in areas considered “low maintenance” such as a woodlot or grove.
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Feast or Famine? By Dave Hanson In the last two years Minnesota’s trees have really been put to the test. A test of extremes; first the winter of 2002-2003 started with an autumn drought and ended with late winter subzero temperatures combined with no snow cover that pushed frost to extreme depths. Late spring and early summer of 2003 started out extremely wet followed by extreme soil moisture deficits June through November. So, we entered the winter of 2003-2004 under drought conditions with many trees already “stressed out.” Minnesota DNR: Forest Insect and Disease Newsletter on drought http://www.dnr.state.mn.us/fid/may04/index.html Any one of the events mentioned above can be serious, but typically not fatal for a healthy tree. These events are referred to as contributing factors to tree decline. Much like insects defoliating a tree, cold and drought events cause stress and reduce the trees ability to create and store nutrients. So, these don’t explain all current tree problems but might have a relationship to some of the problems.
The extreme events such as drought and deep frosts over the last two years have affected the root systems of many trees. During periods of drought soil moisture levels drop. Tree roots require adequate moisture and without it the roots will begin to die. The cold soil temperatures that occurred during the winter of 2002-2003 also had negative affects on the fine roots of trees. These fine roots can be destroyed by dry soils and cold soils. When fine roots are lost the tree loses the ability to take up moisture and nutrients from the surrounding soil. Big deal?
Very big deal! – Reports are coming in regarding trees exhibiting browning of leaf edges, yellowing of leaves, early fall color, or leaves dropping after what appeared to be normal leaf set this spring. Why might this be happening?
First, energy reserves in some of these trees are down due to the root system damage. The damage affects the trees ability to take up nutrients and moisture; thus, photosynthesis is affected leading to a decrease in the creation and storage of nutrients. Bottom line, the stored nutrients become depleted. In some cases this can explain the foliar problems described above.
Feast or Famine?
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Secondly, symptoms like browning of leaf edges or early fall color can be symptoms of drought like conditions. With our cool, wet spring a person might assume that the drought is over and the trees should be fine. However, it takes a minute to explain that while there is now ample soil moisture , due to damaged root systems (loss of fine roots) the trees are not able to utilize the moisture. So, with root damage the tree continues to appear as though it is in a drought.
Not only are we seeing direct relationships to drought, but now the secondary invaders are taking advantage of the trees under stress. During the summer of 2004 Dutch elm disease (DED) is hitting the elm population extremely hard. On another front insect groups are taking advantage of the stressed trees: two-lined chestnut borer on oaks, pine bark beetles attacking various pines, bronze birch borer on birch, ash-lilac borers hitting lilacs and ash trees and this list continues to grow. So, when looking at foliar symptoms in the present, keep in mind the not so distant past and the weather extremes that these trees have had to endure. Quite simply a number of them won’t endure another round of drought stress or insect infestation
This American elm has lost the battle to Dutch Elm Disease (DED).
without some help from us. Some good advice: http://www.cnr.umn.edu/FR/extension/watering.html The following site from Colorado lays out a lot of information regarding drought stress. http://www.colostate.edu/Depts/CoopExt/4DMG/Trees/caring.htm
We are not the only State dealing with “stressed out” trees. “The Colorado Springs Gazette reported on July 13th that the city’s forester Jim Mc-Gannon was looking at the removal of up to 200 prominent city trees related to Colorado’s extended drought. Yet, Colorado Springs was feeling “Ok” with this considering the conditions in neighboring counties where up to 90 percent of the spruce and pine populations were being lost to drought and drought related insect infestations. Work Cited: Ed Sealover, “City Must Cut About 200 Downtown Trees.” The Colorado Springs Gazette, Online. http://msnbc.msn.com/id/5430072, July 13, 2004.
Green Ash exhibiting crown dieback after ash-lilac borer attack.
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FROG AND TOAD BACKYARD HABITATS By: Linda Guertler
Linda is a Dakota County TCA and is a graduate
Frogs and Toads are Welcome Guests
student at the University of Minnesota, MS of Ag in Horticulture.
Lots of gardeners have joined in the latest craze of bird and butterfly gardening by creating gardens that provide food and habitat for them, but relatively few have considered what they can to do to attract our pals from the amphibian world. Frogs and toads should be considered welcome guests and encouraged to take up residence in gardens. Besides being cute, comical and appealing to all ages, they also prefer to dine on the guests most of us prefer not to have visit, such as slugs, earwigs, spiders, grubs, sowbugs, cutworms, and gypsy moths. Over the course of the summer, a single toad can gobble up more than 10,000 of these guys! Even tadpoles get in the act by eating undesirable algae and plankton in ponds. They also pose no danger to you, your pets or plants. Frog and Toad Characteristics Frogs and toads are naturally attracted to areas with ponds, wetlands, bogs and cool, damp places. Because they are amphibians, or “cold-blooded,” they need to move to warm places to increase their body temperature and switch to cooler, moist and shaded places to cool down on a hot day. While both toads and frogs have soft, moist, glandular skin without scales, frogs (left) have smooth skin and must live in water or wet places, and toads (right) have bumpy “warty” skin and live most of their lives on land. Both breed in wet areas in the spring and early summer and lay their eggs in shallow water of flooded areas, or the edge of a wetland or pond. Eggs hatch into larvae called tadpoles that mature over a period anywhere from 6 weeks to two years. The tadpoles have gills and a tail, but after a period of metamorphosis they develop lungs and legs for hopping on land. When
BACKYARD HABITATS their development is complete, they are ready to leave the underwater world to find a new home, hopefully in your back yard. Creating a Frog and Toad Habitat So what can you do to attract frogs and toads to your yard? Most of the things that you can do are quite simple and inexpensive and in most cases these simple steps should attract some frogs or toads the first spring. Before considering the unique needs of frogs and toads separately, there are a number of things that will make or break your frog and toad garden. • Provide rocks or logs in sunny areas for them to bask and warm up in the sun • Scatter logs, brush and other cover in shady areas for cool and protected spots • Don’t allow any runoff of pollutants, including pesticides, fertilizer, gasoline, oil, and salt into low lying areas. They are deadly to frogs and toads because they absorb the chemicals through their skin, and are extremely sensitive to them. Even the drift from lawn care chemicals that gets into a pond can cause the death of tadpoles within a day. • Plant native wetland vegetation in and around ponds and bog areas to provide shelter. Frogs and toads are shy creatures and need protection from predators. See Table 1 for a list of plants to consider based on the amount of sunlight and moisture they require. Use a mixture of upland plants for outer drier areas, moist or wet soil tolerant plants in the center and emergent plants that grow in shallow water in a pond in pots or areas that always have several inches of standing water. • Plant night blooming flowers. They attract moths and frogs and toads love to gobble them up! Try moonflower, hostas, primrose, phlox, cardinal flower and flowering tobacco.
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BACKYARD HABITATS Table 1. Plants for Upland, Wet Soil and Shallow Water Areas Plants for Sunny Areas Plants for Shady Areas Upland (dry edges) Wild Columbine (Aquilegia canadensis) 2’ Bellwort (Uvularia grandiflora) 1’ Sky-blue aster (Aster oolentangiensis) 2.5’
Bloodroot (Sanguinaria canadensis), 1’
Purple prairie clover (Dalea purpurea) 3’
Maidenhair fern (Adiantum pedatum)2.0’
Butterfly weed (Asclepias tuberosa) 3’
Wild geranium (Geranium maculatum)2’
Wild rose (Rosa arkansana), shrub 3’
Solomon’s seal (Polygonatum biflorum) 3’
Purple coneflower (Echinacea purpurea) 4’ Calico aster (Aster lateriflorus) 4.0’ Large-flowered bellwort
American highbush cranberry (Viburnum
Common chokecherry (Prunus virginiana),
(Uvularia grandiflora)
trilobum), shrub 12’
shrub 20’
Photo: Dave Hanson
Black locust (Robinia pseudoacacia, tree
Wet Soil (lowest, wettest soil) Marsh Marigold (Caltha palustris) 1.5’
Crested fern (Dryopteris cristata) 2’
Tall Meadow Rue (Thalictrum polygamum) Marsh fern (Thelypteris palustris), 2’ Blueflag Iris(Iris versicolor) 3’
Jewelweed (Impatiens capensis) 4’
Rush (Juncus spp., many species) Swamp milkweed (Asclepias incarnata) 4’
Cardinal Flower(Lobelia cardinalis) 4’
Prairie cord grass (Spartina pectinata), 4’
American hornbeam (Carpinus caroliniana), tree 25’
Above:Purple coneflower
Sweet Flag (Acorus calamus) 6’
(Clethra alnifolia), shrub 4’
(Echinacea purpurea) Below: Ostrich Fern
Summersweet clethra (sweet pepperbush)
Saskatoon (Amelanchier alnifolia), shrub 20’ Downy serviceberry (Amelanchier arborea),
Photos: Dave Hanson
tree 30’ Smooth alder (Alnus rugosa), shrub 25’
Dogwood (Cornus spp.), 6-10’
Northern white cedar (Thuja occidentalis), tree 30’ Black willow (Salix nigra), tree 60’
Shallow Water (Emergent) Plants Marsh cinquefoil (Potentilla palustris), 1.5’ Sedges (Carex spp.) Arrowhead (Sagittaria latifolia), 3’ Soft rush (Juncus effusus), 3.5’
BACKYARD HABITATS How To Attract Frogs •
Create a wetland or rain garden in low areas of your yard by digging a shallow depression, blocking off natural drainage paths, or diverting rain from gutters to this area. A minimum of 10 feet from the house is recommended to avoid a damp basement. Heavy clay soil is best at retaining water, but to prevent the
•
water from draining away even more, underlay the area with a plastic liner. A more natural look can be created by digging a shallow trench underlain with a liner and covered with river rock on the way to your rain garden. For a more natural and pleasing appearance, create a serpentine shaped stream bed and curving rain garden area.
•
Fill the garden with native plants that will do well based on the amount of sun and moisture provided. Refer to Table 1 for a few suggested native plants to consider. Be sure to place shorter plants in front and progressively taller plants behind them for best viewing of plants.
•
Create a pond by digging a hole with sloping sides and lining it with inexpensive builders plastic or specially made pond liners. Put sand at the bottom and a few logs, rocks or pieces of wood for the little guys to crawl up and get out. Don’t place rocks or other materials that hang over the edges or they will become trapped in the pond with no way to escape. Any width to the pond is fine, but for frogs to have the best shot at over-wintering successfully at the bottom of the pond, a depth of two to three feet is probably best. To increase the chances of over-wintering even more, don’t clean out the bottom when leaves and other material accumulates. Rather than preferring clear sparkling water, frogs find a pond with a muddy, murky bottom more appealing because it provides a place for them to burrow under and hide from predators. In addition, leaves and other debris helps keep the water warmer at the bottom in winter and make it less likely to freeze solid. A pond bubbler or aerator could also be installed to keep a portion of the water open over winter.
How To Attract Toads • Add a toad sized pool by digging a small area a few inches deep and placing a plastic trash can lid, plant saucer or pond liner at soil level. A larger
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BACKYARD HABITATS
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•
version that may also attract frogs can be created by digging a deeper hole and burying a kiddie pool to ground level. Fill the pool with stones and water. A selection of bog (emergent, shallow water) plants in pots may also be added if desired. Be sure to top the pool off with water to prevent totally drying out in extended periods of hot, dry weather. Place a toad home in a shady part of your yard near water. This can be as simple as a clay pot turned upside down with a 3 inch wide by 1.5 inch high hole tapped out (fist drill holes in the shape of the hole you desire). You can also purchase toad homes from gardening stores. Make a toad hole in a shady location by digging a hole 10” X 10” X 10” in the ground and then cover the floor with sand. Place flat stones along the edges of the hole and also across the top for a roof so that the final dimensions
• aren’t any larger than 8” X 8” X 8”. Place a pipe that is 3” wide by 5” long into the opening for the toads to come and go. Shade the opening with small plants. • Toads hibernate underground in winter by digging deep into loose, soft soil. To make their burrowing easier for them, dig a hole that is at least 3 feet deep and 3 feet wide and fill with sand. Cover the surface with leaves, straw or compost to insulate the soil and provide more winter protection. Likely Guests If you create a habit trees and frogs like, they will be coming to visit soon. Shown below are some common Minnesota frogs and toads likely to stop by. Enjoy!
BACKYARD HABITATS
Gray Treefrog
Cope's Gray Treefrog
Hyla versicolor (LeConte, 1825).
Hyla chrysoscelis (Cope, 1880).
Habitat: woodland, forest and urban
Habitat: prairie wetlands, shrub swamps,
yards (clinging to windows feeding on
woodlands and urban yards (clinging to
insects attracted to lights).
windows feeding on insects attracted to
Breeds: Shallow wetlands within or near forested habitat.
lights). Breeds: shallow wetlands, including wet meadows and shrub swamps.
American Toad
Bufo americanus americanus (Holbrook, 1836).
Habitat: forest, woodland, grasslands, residential yards, and gardens. Breeds: temporary wetlands, swamps,
Northern Leopard Frog
Rana pipiens - Northern Leopard Frog (Schreber, 1782
Habitat: grasslands, wet meadows, and forest edges.
shallow bays of lakes, and backwaters of Breeds: Marshes, wetlands, and fishless ponds. rivers, streams and ditches.
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BACKYARD HABITATS For More Information Canadian Wildlife Federation Website. Attracting Wildlife. http:// www.wildaboutgardening.org/en/attracting/section2/ Hamline University website on frogs http://cgee.hamline.edu/frogs/ Jackson, Jeffrey. University of Georgia. 1997.Make a Frog Pond for your Wildlife Garden. Website http://www.forestry.uga.edu/warnell/service/library/index.php3? docID=313&docHistory%5B%5D=13&docHistory%5B%5D=286&docHistory% 5B%5D=290 Jackson, Jeffrey. University of Georgia. 1997. Make a Tree-frog Pond. Website http://www.forestry.uga.edu/warnell/service/library/index.php3? docID=314&docHistory%5B%5D=13&docHistory%5B%5D=286&docHistory% 5B%5D=290 Jackson, Jeffrey. University of Georgia. 1997. An Intelligent Frog. Website http:// www.forestry.uga.edu/warnell/service/library/index.php3? docID=316&docHistory%5B%5D=13&docHistory%5B%5D=286&docHistory% 5B%5D=290 Jackson, Jeffrey. University of Georgia. 1997. Help Frogs Survive the Winter. http:// www.forestry.uga.edu/warnell/service/library/index.php3? docID=315&docHistory%5B%5D=13&docHistory%5B%5D=286&docHistory% 5B%5D=290 Jauron, Richard. 1998. University of Iowa Extension. Trees and Shrubs for Wet Soils. Website http://www.ipm.iastate.edu/ipm/hortnews/1998/8-7-1998/ wetshrubs.html Maryland Cooperative Extension. Home and Garden Information Center. Frogs. http://www.agnr.umd.edu/users/hgic/diagn/wild/frogs.html Megalos, M., J.C. Turner, E.J. Jones, and A.L. Braswell. 1995. North Carolina State University Extension. Pools for Amphibians. http://www.ces.ncsu.edu/nreos/ forest/steward/www19.html Michigan State University Extension website on Frogs and Toads. http:// www.msue.msu.edu/genesee/natres/frog.htm Minnesota Department of Natural Resources. Website on frogs http:// www.dnr.state.mn.us/reptiles_amphibians/frogs_toads/index.html
BACKYARD HABITATS Savonen, Carol. 2002. Oregon State University Extension. Protect amphibians - keep garden nitrogen out of water. http://eesc.orst.edu/agcomwebfile/garden/wildlife/ amphibians.html University of Minnesota Extension bulletin #BU-07447. 2000. Native Plants for Sustainable Landscapes: Establishment and Management of Lakeshores and Gardens. Website acccessed 4-9-04 http://www.extension.umn.edu/distribution/ horticulture/DG7447.html and Native Plant List http://www.extension.umn.edu/ distribution/horticulture/components/7447z.pdf University of Minnesota Extension. Sustainable Urban Landscape Information. Plant Identification and Selection. http://www.sustland.umn.edu/related/ water4.html Photo Credits Laurie Caple watercolor, Hamline University http://cgee.hamline.edu/frogs/resources/tfof.html
John Wilkinson, Kids Ark, UK online http://web.ukonline.co.uk/conker/pond-dip/froggallery.htm Image courtesy of the U. S. Geological Survey, SOFIA website http://sofia.usgs.gov http://allaboutfrogs.org/ Trent University http://www.trentu.ca/biology/tadpole/Webtadpole.htm Jim Wolford http://landscape.acadiau.ca/herpatlas/photopages/jimleop2.html Canadian Wildlife Federation, Diagrams for toad home, hole, pond and hibernaculum from Wild about Gardening website http://www.wildaboutgardening.org/en/dig_dwell_den/section2/
Fitch & Co. at http://www.fitchcom.com/ www.raingardens.org
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BACKYARD HABITATS
Photo courtesy of Joe McDonald, PA Angler and Boater at http://sites.state.pa.us/PA_Exec/Fish_Boat/anglerboater/1999/jf99/leofrogg.htm Sherri Osborn, About Family Crafts at http://familycrafts.about.com/library/weekly/aa081301c.htm The Frog Store http://www.frogstore.com/frogfacts.htm
http://www.Skymall.com
http://homeandgardentreasures.com
Below Left: Cone and needles of White Spruce (Picea glauca) Below Right: Cones and needles of Fraser Fir (Abies fraserii)
Continued from page 1…
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Who’s Confused?
“How is a fir different from a spruce?” Yet, shall we say that there are many educational opportunities out there and bringing an individual to an understanding that not all conifers are pine trees can be challenging!
Let’s begin this article by perpetuating the confusion for a minute. Let’s talk in common names such as “silver pine”; silver pine is native to Minnesota, Wisconsin, Michigan and several Northeastern states from New York to Maine. The range extends across much of Canada from Alberta to Newfoundland and this small to medium sized tree is the Provincial tree of New Brunswick. Think about its true identity for a minute…
Above: Intact pine cones.. Below: Candle growth on Red (Norway) pine (Pinus resinosa)
The name game has kept the pine / spruce / fir confusion alive for generations. For
Photo: Dave Hanson
instance; Eastern hemlock (Tsuga canadensis) a.k.a. hemlock pine, hemlock spruce or just plain spruce. Even our beloved red pine (Pinus resinosa) masquerades in some circles as “Norway” pine to this day. Speculation ties the “Norway” portion of the common name back to Europe’s native Norway spruce (Picea abies). Tracing through all of these aliases you might expect to find a murky, sordid criminal past associated with these individuals, but for the most part it is just plain and simple misidentification.
Ok, lets concentrate on that character referred to as silver pine – any guesses on its true identity? Would the aliases blister pine or fir pine help? Probably not, balsam
Below: whitish undersides of
fir (Abies balsamea) is the common name most of us are familiar with. Before mov-
Serbian spruce (Picea omorika)
ing on to identification characteristics, let’s take a minute to understand those other “common” names. “Silver pine” would be a reference to the silver or white cast that the stomatal lines give the tree. Much like Serbian spruce (Picea omorika), if the balsam fir’s needles are upturned enough, exposing the undersides of the needles, the tree will appear light in color or silvery. Next up on the list is the name “blister pine.” This would be a reference to the resin filled blisters on the trunks of the trees. For many years this resin was actually harvested and put to use by students of biology. Donald Culross Peattie in his book, “A Natural History of Trees of Eastern and Central North America”, writes that the resin was used as a fixative for slip covers when slides were being put together for viewing under a microscope. The
needles. Photo: Dave Hanson
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Who’s Confused? resin sealed the specimen and an added bonus was that the resin had the same refractive qualities as glass, thus creating a sealed, non-distorted specimen to be studied.
Balsam fir is a member of the genus “Abies.” The species name is balsamea and in Minnesota it is the only native fir. Balsam fir is known for its sharply conical form and the wonderful aroma associated with its foliage. A theory regarding this aroma, possibly fact, is that a person exposed to this aroma for a period of time becomes de-sensitized to it. I have not put this one to the test, but Donald Peattie does mention it in his balsam fir write-up.
Underside - stomatal lines - of Abies balsamea needles. Note the top side of the needles are
For most of us the scent of a balsam fir is a definitive identifier. Grabbing on to a branch full of needles releases more scent and is confirmation that this specimen is
dark green and the smallish
a fir tree. The needles have a soft, dull tip which immediately tells you that this is
rounded bud.
not a Colorado blue spruce. Pull off a single needle and attempt to roll it in your
Photo: Dave Hanson
fingers. A fir needle is very flat and will not roll, compare this to the four sided needles of Minnesota’s common spruces. One other strong “fir” characteristic is
New “Pendent” Cone and pointy bud on Douglas Fir in May. Douglas fir is a “false” fir.
the round needle scars on the branches and twigs where needles have fallen off. Now, finish up the close study of the branch by looking at the buds, typical buds on a fir are short and rounded with numerous lateral buds.
Photo: Dave Hanson
There are some very distinct features separating the firs (genus Abies) and the spruces (genus Picea). The previously mentioned flatness of the needles is significant, but one of the more interesting features is the cones. Fir cones are erect on the branch. Cones on a fir do not persist from season to season and often all that is seen on the tree is an erect thin stalk from which all of the cone scales have been shed. Spruce cones on the other hand are pendent (hanging downward) and the cones will retain their scales even as they lie on the ground decomposing. The cone, amongst other characteristics, is also what removes “Douglas Fir” (Pseudotsuga menziesii) from the genus Abies. Douglas fir has pendent cones and sharply pointed buds that separate the species from the true firs, so don’t let the needles fool you.
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Who’s Confused? While balsam fir is the only native, don’t be surprised when you encounter Fraser fir (Abies fraserii) or white fir (Abies concolor). On occasion these members of the family show up as landscape specimens and both can be beautiful trees. Fraser fir and balsam fir can be difficult to distinguish. On Fraser fir, look for a slightly shorter needle in a more compact arrangement completely surrounding the branch. Comparing this to balsam, you will find the balsam needles typically are only on the upper two thirds of the twig or branch. If the Fraser fir is mature and has cones look for bracts extending out between the scales of the cone. These reflexed bracts are very characteristic and identifiable.
White fir has a lighter color needle with a bluish tinge. Hence, the common name white fir. This tree is not easily confused with balsam fir. The needles are flat, upturned and up to 2 inches long. In its native range of the Western United States white fir is a large tree reaching heights of 130 to 150 feet while balsam and Fraser fir tend to be small to medium sized trees at about 30 to 60 feet in height.
The 2 inch long upturned, bluish needles of Abies concolor, white fir.
So, get out there and find yourself a fir tree and compare it to a nice native spruce.
Photo: Dave Hanson
Note the difference in the needles (flattish vs. squarish), cones (erect vs. pendent) and definitely the scent. The scent of a balsam fir is far more pleasant than the scent of a spruce. What is the other common name for white spruce? Oh yes, now I remember: skunk spruce, or cat spruce. I think you get my drift!
Erect cone stalks on Fraser fir Photo: Dave Hanson
Contact Phone Numbers
TCAAG Members:
Program Contacts:
Bob Condon – 952-890-1228
Mimi Hottinger – 507-388-4838
Gary Johnson – 612-625-3765 or grjonson@.umn.edu Dave Hanson – 612-624-1226 or dlhanson@umn.edu Mailing Address: 115 Green Hall, 1530 Cleveland Ave. North, St. Paul, MN 55108
Paula Denman – 612-338-1871
Lisa McDonald - 612-721-2672,
Laurie Drolson – 651-464-9829
Betsy McDonough - 651-779-0437
Bruce Granos – 952-423-5211,
Lu Schmidtke - 651-455-6125
Contacts: Regional Extension Educators: Bob Mugaas – 651-480-7706 Patrick Weicherding, – 763-767-3836 or weich002@umn.edu Gary Wyatt, 507-389-8325 or wyatt@umn.edu County Contacts: Carver County (Jackie Smith) - (952) 442-4496 or smith515@umn.edu Dakota County (Barb Stendahl) – 952-463-8002 or stend004@umn.edu Olmstead County – 507-285-8250 Ramsey County – 651-777-8156 Scott County (Jackie Smith) - (952) 492-5410 or smith515@umn.edu St. Louis County (Bob Olen) – 218-726-7512
Additional Reference Contacts: Debby Newman (Info-U) – 612-624-3263 Don Mueller, DNR Forestry – 651-772-6148 don.mueller@dnr.state.mn.us Ken Holman, DNR Forestry – 651-296-9110 ken.holman@dnr.state.mn.us Paul Walvatne MNDOT – 651-284-3793 Paul.Walvatne@dot.state.mn.us Great River Greening – 651-665-9500 Tree Trust – 651-644-5800
Some of the “milkweeds” common to Minnesota. Below are pictures of 4 of them - for good color photographs visit the TCA website at www.mntca.org link to “Newsletter” -> Summer 2004. Starting in the upper left and proceeding clockwise: Asclepias incarnata, swamp milkweed - pink to rose purple flowers; A. tuberosa, Butterflyweed - orange flower, clear sap; A. verticillata, whorled milkweed - greenish white flower and very thin leaves in whorls; A. syriaca, common milkweed - light pink flower, the one most of us are familiar with.
Photographs: Dave Hanson